A function to calculate hashes on files, using one or more algorithm types.

Get-MultiFileHash.ps1

function Get-MultiFileHash
{
    [CmdletBinding(DefaultParameterSetName = 'Path')]
    param (
        [Parameter(
            Mandatory,
            ParameterSetName = 'Path'
        )]
        [string[]] $Path,

        [Parameter(
            Mandatory,
            ParameterSetName = 'LiteralPath',
            ValueFromPipelineByPropertyName
        )]
        [Alias("PSPath")]
        [string[]] $LiteralPath,

        [Parameter(
            Mandatory,
            ParameterSetName = 'Stream'
        )]
        [IO.Stream] $InputStream,

        [Parameter()]
        [ValidateSet(
            'SHA1', 'SHA256', 'SHA384', 'SHA512',
            'MACTripleDES', 'MD5', 'RIPEMD160'
        )]
        [string[]] $Algorithm = 'SHA256'
    );

    begin
    {
        $Output = [Collections.Generic.List[PSCustomObject]]::new();
    }

    process
    {
        foreach ($Alg in $Algorithm)
        {
            $PSBoundParameters['Algorithm'] = $Alg;

            $Output.Add((Get-FileHash @PSBoundParameters));
        }
    }

    end
    {
        Write-Host;

        $Output `
            | Group-Object -Property Path `
            | ForEach-Object `
            {
                Write-Host "File: $($_.Name)";

                $_.Group `
                    | Select-Object `
                        -Property Algorithm, Hash `
                    | Out-String `
                    | Write-Host;
            };

        return $Output;
    }
}